Electron discharge device



June 30, 1936. E. LOPP ELECTRON DISCHARGE DEVICE Filed July 17, 1935 g ll! 1 1 1 1 1 1 I m I I INVENTOR EDMUND LOPP BY %WW ATTORNEY Patented June 30, 1936 UNITED STATES ELECTRON DISCHARGE DEVICE.

Edmund Liipp, Eindhoven, Netherlands, assignor to N. V. Philips-Gloeilampenfabrieken, Eindhoven, Netherlands Application July 17, 1935, Serial No. 31,768 In Germany August 8, 1934 4 Claims.

To accommodate a large number of high potential lead-in wires various forms of presses have been suggested as, for example, a round press to maintain the insulation between the leading-in wires of the electrodes while the dimensions do not exceed those of a usual tube, although the number of supporting and supply 20 wires could be increased. However, this suggestion fails to produce a marked reduction of the dimensions of the tube.

It is also known to manufacture tubes of very small dimensions for the production of very short 25 waves, the supply wires being taken out at different points of the bulb. It is, however, diflicult to manufacture such tubes by mass-production. The electrode system is arranged in this case in the middle of the bulb.

30 The applicant has found that in the case of a tube having a substantially circular press very small dimensions of the tube may be effected and at the same time satisfactory insulation obtained by lowering or sinking the electrode sys- 35 tem at least partly into the exhaust tube. Thus, a tube according to the invention may be made with a substantial reduction in length and diameter without particular difliculties being encountered with respect to the sealing-in of the 40 current supply wires and the fusing-off of the bulb.

According to my invention the current supply wires and the supporting wires may conveniently be held in spaced relation between two concentric glass tubes which may subsequently be fused together to seal the wires gas tight in the glass. In this case the innermost tube may serve as the exhaust tube while the outermost is formed in 50 the usual manner as a flared tube to which afterwards the bulb of the tube is sealed.

Tubes constructed in accordance with my invention may have low interelectrode capacity and are therefore particularly suitable for use as high 55 frequency amplifiers or detector tubes. My tube,

further, is characterized by the rigid support provided for the electrode assembly.

The invention will be explained more fully with reference to the accompanying drawing which shows in. Figure 1, by way of example, one form 5 of electron tube embodying my invention, and shows in Figure 2 an electron tube of modified construction embodying my invention.

Figure 1 shows anenvelope III of any desired configuration joined in the usual manner at its lower rim II to an inwardly extending or reentrant stem 1. Concentrically within reentrant stem 1 is positioned a second stem or tube 8, hereinafter referred to as an exhaust tube, which is of slightly less diameter than reentrant stem l. Extending longitudinally oi. the envelope and in the annular space between tube 6 and stem 1 are electrode lead-in wires 4 and 5.

Supply and supporting or lead-in wires 4 and 5 respectively are hermetically sealed in by heating and fusing together tube 6 and stem I as shown. The electrode system, which byway of example is constructed in this case as a rectifier, comprises an anode l and a cathode 2. The electrodes are held in spaced relation with the aid of 5 two mica discs 3. One end of the electrode system is centered in the exhaust tube 6 by means of the lower mica plate 3. After the envelope has been exhausted theexhaust tube 6 may conveniently be softened by fire and sealed-off at 8.

The diameter of the anode may be, for example, from 1.5 to 2 mm. and its length may be about 8 mm, while 6 may be a usual exhaust tube with a diameter of about 5 mm. There may, consequently, be obtained a tube having the external dimensions of about 1.5 by 2 cms.

In Figure 2 a second form of electron discharge device is illustrated embodying my invention. In this'modification a cathode ray tube is shown with an electron beam source or "gun 20 positioned 40 concentrically within the exhaust'tube portion 6 of the envelope. Spacer 2| in combination with the relatively heavy lead-in wires 4 and 5 serves to rigidly position the electrode assembly 20 within the envelope.

An electron discharge device constructed in accordance with my invention is characterized by the overall reduction in length of the envelope of the discharge device, by the rigidity of electrode supporting means and by the wide spac- 50 ing, about the annular press, of the electrode lead-in wires.

While my invention has been illustrated in only two specific forms of envelopes, it will be obvious to those skilled in the art that many modifications of electrode assemblies and envelope forms may be made without departing from the scope of my invention. I accordingly desire that my invention be limited only by the prior art and by the limitation of the appended claims.

I claim:

1. An electron discharge device comprising an envelope of insulating material with a reentrant stem, an exhaust tube concentric with said stem, a press comprising a gas tight junction between said stem and tube with lead-in wires sealed therethru, and an assembly of electrodes extending into said tube and connected electrically to said wires.

2. An electron discharge device comprising an envelope with a reentrant glass stem joined at its outer end to the rim of said bulb, a glass tube spaced from and positioned concentrically within said stem, and lead-in wires positioned in the annular space'between said stem and tube, said stem and tube being fused together at their inner ends to seal gas tight said lead-in wires in the glass along the line of fusion, and an assembly of electrodes extending into said exhaust tube and connected to said lead-in wires.

3. A sealed glass vessel comprising a bulb with a reentrant stem extending inwardly from one end thereof, an exhaust tube joined integrally to said stem at the inner end thereof and open at its inner end to form an annular wire sealing portion, a circular series of spaced wires sealed in said annular portion, an electrode assembly in said bulb connected to the wires in said portion and extending into and secured in the open inner end of the exhaust tube.

4. A cathode ray device comprising an envelope, a reentrant stem joined at its outer end to the envelope, a cup-shaped member positioned within said stem and joined at its rim to the inner end of said stem, lead-in wires in the annular space between said member and said stem and sealed gas-tight in the stem, and an electrode assembly extending into said cup-shaped member and connected to said lead-in wires and held in spaced relation to the walls of the member and the envelope by mechanical spacing means and the lead-in wires.

EDMUND LoPP. 

